A polarizing plate used for a liquid crystal display or the like generally includes a polarizer (also referred to as a ‘polarizing film’) in which an iodine-based compound or a dichroic polarizing material is adsorbed and aligned to a polyvinyl alcohol (PVA)-based resin film, arranged in a predetermined direction, and a first and a second polarizer protective films, typically known as triacetylcellulose (TAG) films, are each laminated on both sides of the polarizer via an adhesive.
In recent years, a market for slimmed image display devices, such as slim-type large wall-mounted TV's, mobile-type computers, mobile phones and the like, has been rapidly expanding. In addition, recently, a flexible display device which can maintain display performance even when it is bent like a paper by using a flexible material such as plastic, instead of a conventional glass substrate having no flexibility, gains attention as a next generation display device. Accordingly, there is a need for a polarizing plate, thin in thickness, light in weight and having folding characteristics.
Korean Patent Laid-Open Publication No. 2014-0030060 discloses a circular polarizing plate including a substrate, a retardation layer and a polarizing layer, wherein both the retardation layer and the polarizing layer are coating layers, the total thickness of the retardation layer and the polarizing layer is 10 μm or less, and the polarizing plate contains a dichroic dye. Although the above circular polarizing plate had a sufficient performance as a broadband circular polarizing plate and its thickness satisfied the slimness of a display device, it had an insufficient folding characteristic required for a flexible display, which was problematic.
Accordingly, the development of a polarizing plate having excellent bending resistance which can be applied to a flexible display has been desperately demanded.